This invention relates generally to improvements in motor-driven pumps of the type used, for example, for circulating water in a swimming pool or spa environment or the like. More particularly, this invention relates to an improved, relatively simplified and more compact pump of the type having a seal plate mounted at one end of a motor housing and adapted to support multiple seal components to prevent water leakage past the seal plate and into the motor housing.
Motor-driven pumps for use with a swimming pool or spa are generally known in the art, wherein the pump is adapted to deliver a flow of water under pressure to one or more pool equipment items prior to recirculation of the water to the pool or spa. For example, modern swimming pool and/or spa facilities typically include a filtration unit containing an appropriate filter media for collecting and thus removing solid debris such as fine grit and silt, twigs, leaves, insects, and other particulate matter from water circulated therethrough. A motor-driven pump draws water from the pool and/or spa for delivery to and through the filtration unit, and for subsequent return circulation to the pool and/or spa. This pump is typically operated on a regular schedule to maintain the water in a desired state of cleanliness and clarity. The pump may also circulate the water through additional equipment items such as heating and chemical treatment units and the like.
In some installations, the water can be circulated from the filtration unit to and through an hydraulically driven pool cleaner device mounted in the pool or spa and adapted for dislodging and collecting debris and particulate which has settled onto submerged surfaces. Exemplary hydraulically driven pool cleaner devices are shown and described in U.S. Pat. Nos. 5,863,425; 4,558,479; 4,589,986; and 3,822,754. In some pool equipment configurations, a secondary or so-called booster pump is provided for boosting the pressure of water supplied to the pool cleaner device for insuring proper operation thereof.
Such motor-driven pumps for pool and/or spa use commonly comprise an electric-powered motor of suitable size encased within a motor housing mounted at a suitable and relatively dry location near the associated pool or spa, typically alongside the associated filtration unit and other pool equipment items. The electric motor rotatably drives an output drive shaft which protrudes outwardly through a shaft bearing on the motor housing and is connected to an impeller positioned within a pump chamber defining a suction intake coupled to the body of water within the pool and/or spa, and a discharge outlet coupled to the filtration unit and/or other pool equipment items. A shaft seal arrangement is provided for preventing water leakage from the pump chamber, and resultant axial water migration along the drive shaft in a direction toward the motor housing and into potentially damaging contact with the shaft bearing and/or the electric-powered motor contained therein.
In a common shaft seal arrangement, a ventilated or open cylindrical extension bracket is mounted onto the motor housing in surrounding relation to the protruding drive shaft, and supports a pump housing defining the pump chamber at an outboard end of the extension bracket in axially spaced relation to the motor housing. A primary seal component is provided for sealing passage of the rotatable drive shaft through the pump housing into the pump chamber. With this arrangement, in the event of water leakage past the primary seal component and along the drive shaft in a direction toward the motor housing, such water leakage is normally and harmlessly discharged into the open ventilated space of the extension bracket. A slinger element may be provided on the drive shaft for insuring radial discharge of any such leaking water into the ventilated space of the extension bracket, thereby precluding axial water migration into contact with the motor housing, the shaft bearing, or the electric-powered drive motor.
While such seal arrangements in motor-driven pumps have performed generally in a satisfactory manner, the inclusion of the extension bracket inherently results in a motor-driven pump configuration of extended length which may be unsuitable or undesirable for some mounting locations. In addition, the extension bracket inherently requires the impeller on the drive shaft to be cantilevered a significant axial distance from the shaft bearing on the motor housing, wherein this cantilevered distance can adversely contribute to vibration, noise, and increased bearing wear.
Accordingly, there exists a need for further improvements in and to motor-driven pumps of the type used for circulating water in a swimming pool and/or spa and the like, wherein the extension bracket is eliminated to result in an overall motor-driven pump construction of significantly reduced length, and further wherein an effective seal arrangement is provided for safeguarding the shaft bearing and drive motor against contact with any water leaking along the drive shaft. The present invention fulfills these needs and provides further related advantages.